<?php

namespace winer\Image\Driver;

class GIF {
    /**
     * GIF帧列表
     * 
     * @var array
     */
    private $frames = array();
    
    /**
     * 每帧等待时间列表
     * 
     * @var array
     */
    private $delays = array();
    
    /**
     * 构造方法，用于解码GIF图片
     * 
     * @param string $src GIF图片数据
     * @param string $mod 图片数据类型
     */
    public function __construct($src = null, $mod = 'url') {
        if (! is_null($src)) {
            if ('url' == $mod && is_file($src)) {
                $src = file_get_contents($src);
            }
            
            /* 解码GIF图片 */
            try {
                $de = new GIFDecoder($src);
                $this->frames = $de->GIFGetFrames();
                $this->delays = $de->GIFGetDelays();
            } catch ( \Exception $e ) {
                throw new \Exception('解码GIF图片出错');
            }
        }
    }
    
    /**
     * 设置或获取当前帧的数据
     * 
     * @param string $stream 二进制数据流
     * @return boolean 获取到的数据
     */
    public function image($stream = null) {
        if (is_null($stream)) {
            $current = current($this->frames);
            return false === $current ? reset($this->frames) : $current;
        } else {
            $this->frames[key($this->frames)] = $stream;
        }
    }
    
    /**
     * 将当前帧移动到下一帧
     * 
     * @return string 当前帧数据
     */
    public function nextImage() {
        return next($this->frames);
    }
    
    /**
     * 编码并保存当前GIF图片
     * 
     * @param string $gifname 图片名称
     */
    public function save($gifname) {
        $gif = new GIFEncoder($this->frames, $this->delays, 0, 2, 0, 0, 0, 'bin');
        file_put_contents($gifname, $gif->GetAnimation());
    }

}

/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFEncoder Version 2.0 by László Zsidi, http://gifs.hu
 * ::
 * :: This class is a rewritten 'GifMerge.class.php' version.
 * ::
 * :: Modification:
 * :: - Simplified and easy code,
 * :: - Ultra fast encoding,
 * :: - Built-in errors,
 * :: - Stable working
 * ::
 * ::
 * :: Updated at 2007. 02. 13. '00.05.AM'
 * ::
 * ::
 * ::
 * :: Try on-line GIFBuilder Form demo based on GIFEncoder.
 * ::
 * :: http://gifs.hu/phpclasses/demos/GifBuilder/
 * ::
 * :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 */

class GIFEncoder {
    private $GIF = "GIF89a"; /* GIF header 6 bytes */
    private $VER = "GIFEncoder V2.05"; /* Encoder version */
    
    private $BUF = Array();
    private $LOP = 0;
    private $DIS = 2;
    private $COL = - 1;
    private $IMG = - 1;
    
    private $ERR = Array(
            'ERR00' => "Does not supported function for only one image!",'ERR01' => "Source is not a GIF image!",
            'ERR02' => "Unintelligible flag ",'ERR03' => "Does not make animation from animated GIF source" 
    );
    
    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFEncoder...
     * ::
     */
    public function __construct($GIF_src, $GIF_dly, $GIF_lop, $GIF_dis, $GIF_red, $GIF_grn, $GIF_blu, $GIF_mod) {
        if (! is_array($GIF_src) && ! is_array($GIF_dly)) {
            printf("%s: %s", $this->VER, $this->ERR['ERR00']);
            exit(0);
        }
        $this->LOP = ($GIF_lop > - 1) ? $GIF_lop : 0;
        $this->DIS = ($GIF_dis > - 1) ? (($GIF_dis < 3) ? $GIF_dis : 3) : 2;
        $this->COL = ($GIF_red > - 1 && $GIF_grn > - 1 && $GIF_blu > - 1) ? ($GIF_red | ($GIF_grn << 8) | ($GIF_blu << 16)) : - 1;
    
    for($i = 0; $i < count($GIF_src); $i ++) {
        if (strToLower($GIF_mod) == "url") {
            $this->BUF[] = fread(fopen($GIF_src[$i], "rb"), filesize($GIF_src[$i]));
        } else if (strToLower($GIF_mod) == "bin") {
            $this->BUF[] = $GIF_src[$i];
        } else {
            printf("%s: %s ( %s )!", $this->VER, $this->ERR['ERR02'], $GIF_mod);
            exit(0);
        }
        if (substr($this->BUF[$i], 0, 6) != "GIF87a" && substr($this->BUF[$i], 0, 6) != "GIF89a") {
            printf("%s: %d %s", $this->VER, $i, $this->ERR['ERR01']);
            exit(0);
        }
        for($j = (13 + 3 * (2 << (ord($this->BUF[$i]{10}) & 0x07))), $k = TRUE; $k; $j ++) {
            switch ($this->BUF[$i]{$j}) {
                case "!" :
                    if ((substr($this->BUF[$i], ($j + 3), 8)) == "NETSCAPE") {
                        printf("%s: %s ( %s source )!", $this->VER, $this->ERR['ERR03'], ($i + 1));
                        exit(0);
                    }
                    break;
                case ";" :
                    $k = FALSE;
                    break;
            }
        }
    }
    $this->GIFAddHeader();
    for($i = 0; $i < count($this->BUF); $i ++) {
        $this->GIFAddFrames($i, $GIF_dly[$i]);
    }
    $this->GIFAddFooter();
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFAddHeader...
 * ::
 */
private function GIFAddHeader() {
    $cmap = 0;
    
    if (ord($this->BUF[0]{10}) & 0x80) {
        $cmap = 3 * (2 << (ord($this->BUF[0]{10}) & 0x07));
        
        $this->GIF .= substr($this->BUF[0], 6, 7);
        $this->GIF .= substr($this->BUF[0], 13, $cmap);
        $this->GIF .= "!\377\13NETSCAPE2.0\3\1" . $this->GIFWord($this->LOP) . "\0";
    }
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFAddFrames...
 * ::
 */
private function GIFAddFrames($i, $d) {
    
    $Locals_str = 13 + 3 * (2 << (ord($this->BUF[$i]{10}) & 0x07));
    
    $Locals_end = strlen($this->BUF[$i]) - $Locals_str - 1;
    $Locals_tmp = substr($this->BUF[$i], $Locals_str, $Locals_end);
    
    $Global_len = 2 << (ord($this->BUF[0]{10}) & 0x07);
    $Locals_len = 2 << (ord($this->BUF[$i]{10}) & 0x07);
    
    $Global_rgb = substr($this->BUF[0], 13, 3 * (2 << (ord($this->BUF[0]{10}) & 0x07)));
    $Locals_rgb = substr($this->BUF[$i], 13, 3 * (2 << (ord($this->BUF[$i]{10}) & 0x07)));
    
    $Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 0) . chr(($d >> 0) & 0xFF) . chr(($d >> 8) & 0xFF) . "\x0\x0";
    
    if ($this->COL > - 1 && ord($this->BUF[$i]{10}) & 0x80) {
        for($j = 0; $j < (2 << (ord($this->BUF[$i]{10}) & 0x07)); $j ++) {
            if (ord($Locals_rgb{3 * $j + 0}) == (($this->COL >> 16) & 0xFF) && ord($Locals_rgb{3 * $j + 1}) == (($this->COL >> 8) & 0xFF) && ord($Locals_rgb{3 * $j + 2}) == (($this->COL >> 0) & 0xFF)) {
            $Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 1) . chr(($d >> 0) & 0xFF) . chr(($d >> 8) & 0xFF) . chr($j) . "\x0";
            break;
        }
    }
}
switch ($Locals_tmp{0}) {
    case "!" :
        $Locals_img = substr($Locals_tmp, 8, 10);
        $Locals_tmp = substr($Locals_tmp, 18, strlen($Locals_tmp) - 18);
        break;
    case "," :
        $Locals_img = substr($Locals_tmp, 0, 10);
        $Locals_tmp = substr($Locals_tmp, 10, strlen($Locals_tmp) - 10);
        break;
}
if (ord($this->BUF[$i]{10}) & 0x80 && $this->IMG > - 1) {
    if ($Global_len == $Locals_len) {
        if ($this->GIFBlockCompare($Global_rgb, $Locals_rgb, $Global_len)) {
            $this->GIF .= ($Locals_ext . $Locals_img . $Locals_tmp);
        } else {
            $byte = ord($Locals_img{9});
            $byte |= 0x80;
            $byte &= 0xF8;
            $byte |= (ord($this->BUF[0]{10}) & 0x07);
            $Locals_img{9} = chr($byte);
            $this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);
        }
    } else {
        $byte = ord($Locals_img{9});
        $byte |= 0x80;
        $byte &= 0xF8;
        $byte |= (ord($this->BUF[$i]{10}) & 0x07);
        $Locals_img{9} = chr($byte);
        $this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);
    }
} else {
    $this->GIF .= ($Locals_ext . $Locals_img . $Locals_tmp);
}
$this->IMG = 1;
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFAddFooter...
 * ::
 */
private function GIFAddFooter() {
$this->GIF .= ";";
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFBlockCompare...
 * ::
 */
private function GIFBlockCompare($GlobalBlock, $LocalBlock, $Len) {

for($i = 0; $i < $Len; $i ++) {
    if ($GlobalBlock{3 * $i + 0} != $LocalBlock{3 * $i + 0} || $GlobalBlock{3 * $i + 1} != $LocalBlock{3 * $i + 1} || $GlobalBlock{3 * $i + 2} != $LocalBlock{3 * $i + 2}) {
    return (0);
}
}

return (1);
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFWord...
 * ::
 */
private function GIFWord($int) {

return (chr($int & 0xFF) . chr(($int >> 8) & 0xFF));
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GetAnimation...
 * ::
 */
public function GetAnimation() {
return ($this->GIF);
}
}

/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFDecoder Version 2.0 by László Zsidi, http://gifs.hu
 * ::
 * :: Created at 2007. 02. 01. '07.47.AM'
 * ::
 * ::
 * ::
 * ::
 * :: Try on-line GIFBuilder Form demo based on GIFDecoder.
 * ::
 * :: http://gifs.hu/phpclasses/demos/GifBuilder/
 * ::
 * :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 */

class GIFDecoder {
private $GIF_buffer = Array();
private $GIF_arrays = Array();
private $GIF_delays = Array();
private $GIF_stream = "";
private $GIF_string = "";
private $GIF_bfseek = 0;

private $GIF_screen = Array();
private $GIF_global = Array();
private $GIF_sorted;
private $GIF_colorS;
private $GIF_colorC;
private $GIF_colorF;

/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFDecoder ( $GIF_pointer )
 * ::
 */
public function __construct($GIF_pointer) {
$this->GIF_stream = $GIF_pointer;

$this->GIFGetByte(6); // GIF89a
$this->GIFGetByte(7); // Logical Screen Descriptor

$this->GIF_screen = $this->GIF_buffer;
$this->GIF_colorF = $this->GIF_buffer[4] & 0x80 ? 1 : 0;
$this->GIF_sorted = $this->GIF_buffer[4] & 0x08 ? 1 : 0;
$this->GIF_colorC = $this->GIF_buffer[4] & 0x07;
$this->GIF_colorS = 2 << $this->GIF_colorC;

if ($this->GIF_colorF == 1) {
$this->GIFGetByte(3 * $this->GIF_colorS);
$this->GIF_global = $this->GIF_buffer;
}
/*
 *
 * 05.06.2007.
 * Made a little modification
 *
 *
 * - for ( $cycle = 1; $cycle; ) {
 * + if ( GIFDecoder::GIFGetByte ( 1 ) ) {
 * - switch ( $this->GIF_buffer [ 0 ] ) {
 * - case 0x21:
 * - GIFDecoder::GIFReadExtensions ( );
 * - break;
 * - case 0x2C:
 * - GIFDecoder::GIFReadDescriptor ( );
 * - break;
 * - case 0x3B:
 * - $cycle = 0;
 * - break;
 * - }
 * - }
 * + else {
 * + $cycle = 0;
 * + }
 * - }
 */
for($cycle = 1; $cycle;) {
if ($this->GIFGetByte(1)) {
    switch ($this->GIF_buffer[0]) {
        case 0x21 :
            $this->GIFReadExtensions();
            break;
        case 0x2C :
            $this->GIFReadDescriptor();
            break;
        case 0x3B :
            $cycle = 0;
            break;
    }
} else {
    $cycle = 0;
}
}
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFReadExtension ( )
 * ::
 */
private function GIFReadExtensions() {
$this->GIFGetByte(1);
for(;;) {
$this->GIFGetByte(1);
if (($u = $this->GIF_buffer[0]) == 0x00) {
    break;
}
$this->GIFGetByte($u);
/*
 * 07.05.2007.
 * Implemented a new line for a new function
 * to determine the originaly delays between
 * frames.
 *
 */
if ($u == 4) {
    $this->GIF_delays[] = ($this->GIF_buffer[1] | $this->GIF_buffer[2] << 8);
}
}
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFReadExtension ( )
 * ::
 */
private function GIFReadDescriptor() {
$GIF_screen = Array();

$this->GIFGetByte(9);
$GIF_screen = $this->GIF_buffer;
$GIF_colorF = $this->GIF_buffer[8] & 0x80 ? 1 : 0;
if ($GIF_colorF) {
$GIF_code = $this->GIF_buffer[8] & 0x07;
$GIF_sort = $this->GIF_buffer[8] & 0x20 ? 1 : 0;
} else {
$GIF_code = $this->GIF_colorC;
$GIF_sort = $this->GIF_sorted;
}
$GIF_size = 2 << $GIF_code;
$this->GIF_screen[4] &= 0x70;
$this->GIF_screen[4] |= 0x80;
$this->GIF_screen[4] |= $GIF_code;
if ($GIF_sort) {
$this->GIF_screen[4] |= 0x08;
}
$this->GIF_string = "GIF87a";
$this->GIFPutByte($this->GIF_screen);
if ($GIF_colorF == 1) {
$this->GIFGetByte(3 * $GIF_size);
$this->GIFPutByte($this->GIF_buffer);
} else {
$this->GIFPutByte($this->GIF_global);
}
$this->GIF_string .= chr(0x2C);
$GIF_screen[8] &= 0x40;
$this->GIFPutByte($GIF_screen);
$this->GIFGetByte(1);
$this->GIFPutByte($this->GIF_buffer);
for(;;) {
$this->GIFGetByte(1);
$this->GIFPutByte($this->GIF_buffer);
if (($u = $this->GIF_buffer[0]) == 0x00) {
    break;
}
$this->GIFGetByte($u);
$this->GIFPutByte($this->GIF_buffer);
}
$this->GIF_string .= chr(0x3B);
/*
 * Add frames into $GIF_stream array...
 */
$this->GIF_arrays[] = $this->GIF_string;
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFGetByte ( $len )
 * ::
 */

/*
 *
 * 05.06.2007.
 * Made a little modification
 *
 *
 * - function GIFGetByte ( $len ) {
 * - $this->GIF_buffer = Array ( );
 * -
 * - for ( $i = 0; $i < $len; $i++ ) {
 * + if ( $this->GIF_bfseek > strlen ( $this->GIF_stream ) ) {
 * + return 0;
 * + }
 * - $this->GIF_buffer [ ] = ord ( $this->GIF_stream { $this->GIF_bfseek++ } );
 * - }
 * + return 1;
 * - }
 */
private function GIFGetByte($len) {
$this->GIF_buffer = Array();

for($i = 0; $i < $len; $i ++) {
if ($this->GIF_bfseek > strlen($this->GIF_stream)) {
    return 0;
}
$this->GIF_buffer[] = ord($this->GIF_stream{$this->GIF_bfseek ++});
}
return 1;
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFPutByte ( $bytes )
 * ::
 */
private function GIFPutByte($bytes) {
for($i = 0; $i < count($bytes); $i ++) {
$this->GIF_string .= chr($bytes[$i]);
}
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: PUBLIC FUNCTIONS
 * ::
 * ::
 * :: GIFGetFrames ( )
 * ::
 */
public function GIFGetFrames() {
return ($this->GIF_arrays);
}
/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFGetDelays ( )
 * ::
 */
public function GIFGetDelays() {
return ($this->GIF_delays);
}
}
